rtc: ia64: allow other architectures to use EFI RTC

Currently, the rtc-efi driver is restricted to ia64 only. Newer
architectures with EFI support may want to also use that driver. This
patch moves the platform device setup from ia64 into drivers/rtc and
allow any architecture with CONFIG_EFI=y to use the rtc-efi driver.

Signed-off-by: Mark Salter <[e-mail]>
Cc: Alessandro Zummo <[e-mail]>
Cc: Tony Luck <[e-mail]>
Cc: Fenghua Yu <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/ia64/kernel/time.c

···
 	.name =		"timer"
 };
 
-static struct platform_device rtc_efi_dev = {
-	.name = "rtc-efi",
-	.id = -1,
-};
-
-static int __init rtc_init(void)
-{
-	if (platform_device_register(&rtc_efi_dev) < 0)
-		printk(KERN_ERR "unable to register rtc device...\n");
-
-	/* not necessarily an error */
-	return 0;
-}
-module_init(rtc_init);
-
 void read_persistent_clock(struct timespec *ts)
 {
 	efi_gettimeofday(ts);

drivers/rtc/Kconfig

···
 
 config RTC_DRV_EFI
 	tristate "EFI RTC"
-	depends on IA64
+	depends on EFI
 	help
 	  If you say yes here you will get support for the EFI
 	  Real Time Clock.

drivers/rtc/Makefile

···
 obj-$(CONFIG_RTC_CLASS)		+= rtc-core.o
 rtc-core-y			:= class.o interface.o
 
+ifdef CONFIG_RTC_DRV_EFI
+rtc-core-y			+= rtc-efi-platform.o
+endif
+
 rtc-core-$(CONFIG_RTC_INTF_DEV)	+= rtc-dev.o
 rtc-core-$(CONFIG_RTC_INTF_PROC) += rtc-proc.o
 rtc-core-$(CONFIG_RTC_INTF_SYSFS) += rtc-sysfs.o

drivers/rtc/rtc-efi-platform.c

···
+/*
+ * Moved from arch/ia64/kernel/time.c
+ *
+ * Copyright (C) 1998-2003 Hewlett-Packard Co
+ *	Stephane Eranian <[e-mail]>
+ *	David Mosberger <[e-mail]>
+ * Copyright (C) 1999 Don Dugger <[e-mail]>
+ * Copyright (C) 1999-2000 VA Linux Systems
+ * Copyright (C) 1999-2000 Walt Drummond <[e-mail]>
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/efi.h>
+#include <linux/platform_device.h>
+
+static struct platform_device rtc_efi_dev = {
+	.name = "rtc-efi",
+	.id = -1,
+};
+
+static int __init rtc_init(void)
+{
+	if (efi_enabled(EFI_RUNTIME_SERVICES))
+		if (platform_device_register(&rtc_efi_dev) < 0)
+			pr_err("unable to register rtc device...\n");
+
+	/* not necessarily an error */
+	return 0;
+}
+module_init(rtc_init);